Ede's 12v90

My friend has a 91 maxima. I know wrong side of the world but I figured that this should be universal.
She said that her car wouldn't start so I went over to check it out. The battery was dead. I hooked up my jumper cables to try to jump the car. The starter motor would turn, but only ~45* and then it would just poop out and twitch (you could hear a click that coincided with the twitch).
It could be the alternator since the battery is dead. But if it's just the alternator then why would the started not roll over? It could be the starter, but then why would the battery be dead?
I know you can start the car and unplug the battery to test the alternator. If the enging dies then its the alternator, but I'm not sure how you can test the starter. The car's an automatic so push starting it isn't an option. She just got a new battery about six months ago, so it could be that the battery is just bad, and it's too resistive to allow the full current from my car to get the starter juices a flowin.
Any input would be great. Very worst case scenario I can think of is that it's the alternator, and the starter, but then it's kinda odd that both would blow at the exact same time. I'm not sure if the starter has ever been changed, but with 165k on the car, I'm sure the alternator has been changed in atleast the past 75k. I'm not sure of the duration of a starter motor. Thanks in advance, she sends her gratitude as well.

Greg PAW - MS

unbolt the cables from her battery and hook em directly to your car. Then you'll know if it's the battery. If the starter is stil not turning over with the "known good" power supply that is your car then I would say it's the starter.

Ede's 12v90

yeah i just thought of that too

Ede's 12v90

no cigar, the starter does the same thing when i just hook up the terminals, w/o the batt...........

Mr.D-'97 A4q 12v

If the car still will not start with the good battery than its probably the starter. The car can usually start even if the altenator is bad.

I just went through a bad altenator on my wife's car.

Greg PAW - MS

Was the car getting increasingly difficult to start before the starter started dying? Starters don't usually fail suddenly, they usually fail over a certain period. A very sudden failure along with the fact that it turns 1/4turn and then jams but keeps trying might indicate that it's working but it just can't budge the flywheel or driveplate in this case... I don't know much about automatic transmissions, so I don't know if pushing the car while in gear would turn the crank, but if it does it might fre whatever the blockage is.

Just a possible theory...

Ede's 12v90

only good part about that damn car was that it was literally a 30 min job to change the alternator. Don't get me started on the engine it made run though. All I have to say is that 110hp and 3800lb curb weight don't mix well.

Mr.D-'97 A4q 12v

The altenator was super easy to replace on my wife's car, too. Right on top. ;-)

patience

When the battery stops accepting charge or won't hold one- then the alternator has to work harder longer into more load. Can kill/hurt them(perhaps one diode fries or the like).
Then when you replace battery, tired alternator does not support it properly and it dies young... vicious circle.

Now, and this is a stretch, if the starter was getting hard to turn and took more juice for longer... It could push a marginal battery/alternator pair over the edge.

Point, get both battery and alternator checked when one dies under suspicious circumstances, if you can't "always" check both.